GB2195402A - A method of power generation and it's use in a propulsion device - Google Patents

Abstract

The method uses a compressed primary fluid (eg gas) to heat and vaporize under pressure a liquid secondary fluid and the use of the resultant vapour/gas/steam or mixed said compressed primary medium and said vapor/gas steam for power generation purposes in for example an expansion device. Various methods of compressing the medium and various uses of the method (eg in gas turbine, i.c. oil, two stroke, four stroke engines) are contemplated. In a propulsion device application, ambient air compressed in cowling 6 transfers heat to a chamber 2 via fins 4 whereby liquid CO2 supplied by injector 1 at an atomiser 3, is vapourised and ejected through jet-pipe 7 via a nozzle 5, thus assisting, by induction, the air flow through the cowling 6. A pump 10 is used during starting, thereafter the injector 1 is stated to be driven by fluid bled through line 9. A three-way valve 8 enables transfer from a liquid CO2 supply to a liquid air supply at high altitudes. The fluids leaving the pipe 7 may be used to drive a turbine driving a fan or an airscrew. <IMAGE>

Description

SPECIFICATION A method of power generation This invention relates to a method of power generation.

Conventional power plants in common use derive their energy from atomic reaction coal and oil fuel combustion or a head of water.

These methods of power generation have the disadvantage that the fuel used is relatively expensive and water driven plants are unsuitable for general use. The supply of coal, oil and atomic fuel is also exhaustible.

The total heat of a compressed gas or gaseous fluid, such as air, which I will term the primary fluid, equals the sum of the total heat of said primary fluid before its compression and the energy of the compression work.

Considering the above fact it seems possible that if the heat of a compressed such primary fluid is utilized in a steam or a mixed steam and said primary fluid power plant, for example the power plants disclosed in my U.K. patent specifications numbers 2086483B and 2110305A, even allowing for any efficiency loss in the primary fluid compression means, the useful power output of said plant could exceed the energy requirement to compress said primary fluid.

According to the invention, a method of power generation consists in the compression of a gas or gaseous primary fluid, the use of heat derived from said compressed primary medium to convert a liquid secondary fluid into steam, and the utilization of said steam or a mixed said compressed primary fluid and said steam quantity and any spent said primary fluid in a heat-engine provision and optionally to effect said primary fluid compression.

The steam formation may or may not be at or above the critical temperature specified in my aforementioned specification number 2086483B viz. perhaps at a lower temperature.

With this invention the primary and secondary fluids used are desirably non-corrosive and chemically highly inert media unless otherwise required, in a condensing plant the spent primary fluid leaving e.g. the steam producing means usually being expanded and employed as the coolant of the secondary fluid steam condensing means and finally recycled. For example, the use of a nitrogen primary fluid and a freon or water secondary fluid is practical, although in a mixed fluid jet propulsion unit configuration ambient air primary fluid and a liquid air or oxygen secondary fluid, later perhaps to support or help support fuel combustion at high altitude, might be used, such a plant then being only partly steam or mixed steam and primary fluid powered.

In a mixed fluid plant the secondary fluid is normally sprayed into the hot compressed primary fluid and flashed into steam in a mixing chamber containing said primary fluid. The combustion chamber of an air breathing turbojet engine is the mixing chamber in one application of this method, secondary fluid being sprayed into said chamber through a single or multiple atomizers e.g. a ring of such devices placed at or around the entrance to said chamber. In other applications the mixing chamber is the cylinder or rotor chamber of a two or four-stroke engine or also acts as a reservoir for the secondary fluid and functions as an internally heated boiler vessel, the said secondary fluid optionally being pre-heated, for example by combustion gas heat, ram air heat in a hypersonic jet propulsion unit layout or electrical heating means, in non-condensing designs before use.

In a purely steam producing application of the method the compressed primary fluid heats a boiler fed with the secondary fluid externally and the spent said primary fluid is expanded possibly through an auxiliary heatengine, the said boiler being a flash, multitubular or any other kind of such steam generator.

The heat-engine provision may include jet propulsion nozzle such expansion devices.

The use of a secondary liquid fluid having a low specific heat is preferable, since the heat requisite for its evaporation in this case would be less. The use of a such fluid having a low boiling temperature may similarly be advantageous in the respect that, in a non-condensing application of the method, such as a turbo-jet engine example, the consumption of said fluid, which is injected continuously in this particular instance, could so be reduced.

However water, preferably distilled, is the cheapest such fluid and might be mixed e.g.

with a more volatile soluble fluid lowering the overall boiling temperature of said secondary medium.

The design of two and four-stroke power plants is similar to that of oil fuel driven such plants in a specific application of the method, the secondary fluid being sprayed into, for example the cylinder or rotor chamber of the plant, at the end of each primary fluid compression stroke or phase and vaporized, but the compression of said primary fluid could be higher, the heavy supercharging of said cylinder or rotor chamber optionally being used to help obtain said higher compression. Carburettor primary and secondary fluid mixing design may be practical in two and four-stroke power plants, the use of a less volatile secondary fluid or a reduced division of said secondary mediium in the carburettor venturi system to prevent its vaporization before the end of the primary and secondary fluid mixture compression possibly being featured.In either case the secondary fluid cools the plant, no other cooling provision or means probably being necessary.

The invention may be applied to most kinds of thermal power plants, whether the primary fluid is compressed by a mechanical compressor or a jet type unit or by ram action due to the forward motion of an aircraft installation or even due to the velocity of exhaust fluid leaving the heat-engine provision or the plant's condenser or by the action of said heat-engine provision itself or combined such means, whether said mechanical compressor is driven by said heat-engine provision or by independent means, for example an electric motor, or whether said primary fluid is secondary fluid steam recycled or remaining in the plant's working fluid circuit, such as an engine cylinder, or a different medium or mixed steam and said different fluid.

The invention may also be applied to continuous or intermittent cycle power plants, for example a two or four-stroke piston engine or a condensing gas turbine engine in accordance with my aforesaid patent specifications, in which the condenser is cooled partly by additional refrigerative means i.e. additional to its normal cooling means, waste heat from which is utilized to heat said piston engines' cylinders or recycled primary fluid feeding e.g. said gas turbine engine's compressor or mixing chamber; in which said engine cylinders are alternatively heated electrically, in which said condenser also acts as a reservoir for the primary and secondary fluids or said secondary fluid is sprayed into the mixing chambers of such power plants by displacement pumps, steam injectors, jet primary fluid compressors, pressurized said fluid fed metreing devices, such as an engine driven rotary disc valve, or the like, or in which the mixing chamber location of, for example a turbo-jet engine fuel burning embodiment, is up or downstream of said plant's fuel combustion zone e.g. in said plant's compressed primary fluid delivery system or its tail-pipe section, the primary and secondary fluids or secondary fluid steam in this case being further heated by the fuel combustion, said cylinder heating being for the purpose of enhancing the secondary fluid va vaporization in the cylinder assemblies.

In all instances the primary fluid compression provision needs to function before each start of a power plant using this power generation method can be effected, although in a purely steam producing and utilizing power plant of said kind for example, steam can be raised by heating the plant's boiler by independent means, such as a fuel burner or an electric heater. Electric heating plugs provided e.g. in the cylinder heads of intermittent cycle piston plants may also be activated during the starting period of such power plants to assist the steam forming process in their cylinders.

Because no fuel is utilized in the basic power generation method hereinbefore described, the cost of power so generated is substantially, in all cases, reduced.

Typical steam boilers heated by compressed primary fluid and jet primary fluid compressor systems such as I have specified are disclosed in my specifications aforementioned, the use of a gas generator unit to compress the primary fluid heating a steam boiler is also disclosed therein, this latter method of said fluid compression being suitable for use with my present invention. Such a gas generator unit is in accordance with my U.K. patent specification No. 1,100,903 or is a mixed fluid unit according to my present invention.

The use of ambient air or water cooled secondary fluid steam condensers is practical, in aircraft power plants for example, the relative wind being utilized in this way.

In a variation of the basic concept of this invention, the spent cold expanded primary fluid leaving a secondary fluid steam boiler heating means or an associated auxiliary heatengine is utilized remotely, for example for refrigeration or freezing purposes. Conversely, some of the generated power is obtained in the form of heat, for example by directing a portion of the formed steam, mixture or compressed primary fluid through a heat-exchanger supplying hot air for room heating, or plants may be designed to function exclusively as heat generators.

The method of power generation now disclosed may be used by any i.c. heavy oil engine, jet propulsion unit or gas turbine engine primarily simply by substituting the liquid secondary medium for the fuel normally supplied to these power plants and by the disuse of cylinder cooling provisions, where appropriate.

Referring to the accompanying drawings which are purely diagrammatic representations of a rocket motor working according to the invention: Liquid carbon-dioxide secondary fluid fed by a steam injector 1 into a cylindrical copper chamber 2 through an atomizer 3 is vaporized by heat conducted to said chamber by longitudinal fins 4 e.g., disposed radially around said chamber's outer surfaces and a nozzle 5 provided at the steam outlet end of said chamber, from anambient air primary fluid flow induced through a cowling 6 extending to a jetpipe 7. The generated CO2 steam is ejected through jet-pipe 7 by nozzle 5 and helps to induce the air-flow through cowling 6, which encircles chamber 2. The mixed steam and primary fluid air expands through jet-pipe 7 and produces a thrust reaction.At high altitude the carbon-dioxide supply to injector 1 is stopped by a three way valve 8 and liquid air is fed by said injector, which is operated by steam led to it by a pipe 9 from chamber 2, to atomizer 3. This liquid air secondary fluid is converted into steam in chamber 2 in the same way as the carbon-dioxide such fluid and operates the motor, but has a higher energy output due to its lower boiling temperature, although unsuitable for low altitude use owing to its ice forming effect on fins 4. At very high speed the air entering cowling 6 is further compessed viz. above atmospheric pressure, by ram action, thus increasing its temperature.

In a modification of this rocket motor the steam leaving nozzle 5 or the mixture expanded through pipe 7 is fed to a turbine driving a propulsion fan or an airscrew. In the former instance the steam leaving the turbine is ejected by an embodied exhaust nozzle through pipe 7 and induces the primary airflow through cowling 6.

When starting the motor, liquid carbon-dioxide is fed to atomizer 3 by an electrically driven pump 10.

In a second modification of this motor, the nozzle 5 is placed in a suitable venturi upstream of chamber 2, the steam jet ejected through said nozzle acting to compress the air entering cowling 6 before the expansion of said steam and air (mixture) through pipe 7.

In a third modification of this motor, the air entrained by cowling 6 is drawn through an air turbine 11 operating to drive a turbo-compressor (not illustrated) feeding compessed air primary fluid into chamber 2, the fins 4 optionally being omitted from the design or acting to provide only a portion of the heat requirement of the secondary fluid supplied to said chamber.

In a so called afterburner configuration, which is of course applicable to any jet propulsion unit embodying my present invention, fuel is injected into jet-pipe 7 and ignited and burnt therein to increase the motor's developed thrust.

The invention moreover includes superheating of the secondary fluid steam by the heat of the compressed primary fluid, for example by the passage of said steam, in steam operated power plants using the method, through superheating means exposed to said primary medium.

The expression heat-engine in this description refers to any device or devices in which the generated steam or mixture is utilized, whatever the nature of the power thereby produced.

The ambient air primary fluid used by the rocket motor described is conveniently already compressed but, in practice, the primary fluid is compressed or further compressed to any chosen pressure above absolute zero.

The pressurized secondary fluid supply lines of the example shown in the drawing would need to incorporate clack valves. If desired, the CO2 liquid feed to atomizer 3 may be effected solely by pump 10.

For all practical purposes the heat obtainable from the compressed primary fluid and, therefore, the power generated, is largely proportional to the difference in the temperature of said fluid and the boiling temperature of the secondary medium, not merely to the work performed in compressing said primary fluid.

On the other hand, if hypothetically the temperature of the primary fluid before its compression was zero absolute, this might not be so, since the compression work requirement of said fluid would be much greater, in fact equal to the total heat of the compressed said fluid.

Claims (10)

1. A method of power generation consisting in the compression of a gas or gaseous primary fluid, the use of heat derived from said compressed primary medium to convert a liquid secondary fluid into steam, and the utilization of said steam or a mixed said compressed primary fluid and said steam quantity and any spent said primary fluid in a heatengine provision and optionally to effect said primary fluid compression.

2. A rocket motor working according to the power generation method defined in Claim 1, comprising a cylindrical chamber having an outlet nozzle at one end, a means for the injection of a volatile secondary liquid fluid in atomized form into said chamber's opposite end, and radially and longitudinally disposed heat conducting fins around its outer surface; a cowling through which an ambient air primary heating fluid stream is induced over said chamber and its fins encircling the said chamber and fin assembly, an air ejector inducing or helping to induce said primary fluid flow and operated by steam formed by the vaporization of said volatile liquid in said chamber and exhausted therefrom via said nozzle outlet, a jet-pipe through which the mixed spent primary fluid and said steam leaving said air ejector expands, to atmosphere or to a turbine and produces a thrust reaction, and a provision for the pressurization and supply of said volatile liquid, said steam exhausted through said nozzle outlet alternatively being fed to a turbine prior to utilization in said air ejector, said turbines acting to drive airscrews or propulsion fans.

3. A rocket motor as in Claim 2, including a copper cylindrical chamber, fin and outlet nozzle assembly.

4. A rocket motor as in Claim 2 or Claim 3, wherein the provision for pressurizing and the supply of the volatile liquid to the injection means thereof is a steam injector.

5. A rocket motor as in any of Claims 2 to 4, wherein the volatile liquid employed as the secondary fluid is liquid CO2 when starting the working cycle of said motor and during its (said motor's) operation at low or medium altitude and liquid air at a higher altitude.

6. A rocket motor as in any of Claims 2 to 5, including a provision to ignite and burn fuel injected into its jet-pipe, in the mixture exhausted therethrough.

7. A rocket motor as in any of Claims 2 to 6, wherein the primary fluid (air) ejector is placed upstream or down-stream of the cylin drical chamber.

8. A rocket motor as in any of Claims 2 to 7, including an electrically driven volatile liquid secondary fluid pump acting to feed CO2 said fluid, when starting the working cycle of said motor only or, as appropriate, continuously, to said fluid's injection means.

9. A rocket motor as in any of Claims 2 to 8, modified in that the (main) primary air entrainment is through an air turbine rotated by said air and operating to drive a turbo-compressor feeding additional compressed such air, providing some of the vaporization heat requirement of the volatile liquid secondary fluid, into the cylindrical chamber.

10. A method of power generation and apparatus, substantially as hereinbefore described; in the pertinent instances, with reference to the accompanying single figure drawings.